denisidoro / docoptsh

A command line argument parser written in pure Bash

Docoptsh

A command-line argument parser written in pure Bash, for size-constrained systems, such as Android devices running Termux, Windows as a secondary OS using the Subsystem for Linux or minimal Docker containers.

It implements a subset of the docopt language, which should be enough for most scripting needs.

Examples

Given the documentation below...

Ship helpers

Usage:
  ship [options] move <x> <y>
  ship [fast] create
  ship paint (green|red)

Options:
  -f --force             Ignore ongoing movement
  -t --target <target>   Ship-id [default: 0] 

...the following script calls are valid and will set the variables accordingly:

ship move 10 30
ship create
ship fast create
ship paint red
ship -ft=2 10 30
ship -f --target 2 10 30

Real-world examples can be found in my dotfiles.

Usage

./docoptsh -h "Script description\nUsage: ..." : move -t=2 10 30

Unsupported syntax

As of now, most nested structures won't work, such as:

ship [--shape <shape>]
ship (fast|[<style>])

Also, variadic arguments won't work as well:

ship destroy -- <ids>...

Alternatives

If the system running the script has Python installed, such as a batteries included, personal computer, you probably want to use the Python-based docopt parser.

Otherwise, if compiling and using a binary for a given OS and processor architecture isn't a concern, you can use the Go-based docopt parser.